Heretofore, for the purpose of controlling light distribution characteristics and thereby increasing an extraction efficiency of light from an LED package in which an LED chip is mounted, a bowl-shaped envelope made of white resin has been provided in the LED package. In such an LED package, an LED chip is mounted on a bottom surface of the envelope, and then, transparent resin is filled in the envelope to bury the LED chip. Such an envelope is often formed of a polyamide-based thermoplastic resin (for instance, refer to JP-A 2004-274027 (Kokai)).
In recent years, along with expansion of the application range of LED packages, there has been a demand for LED packages to become more durable. Meanwhile, the amount of light and heat emitted from an LED chip increases along with an increase in an output power of the LED chip, which in turn, causes degradation of a resin portion sealing the LED chip to proceed easily. In addition, along with expansion of the application range of LED packages, a further cost-reduction has been demanded.